Shead, 28, originally signed on with the Seahawks as an undrafted free agent out of Portland State back in 2012. He returned to the Seahawks on a one-year exclusive rights contract for the 2016 season.
Seattle declined to tender Shead a contract as a restricted free agent back in 2017 but later brought him back on a one-year, $1.5 million contract. From there, he signed a one-year, $3.5 million contract with the Lions in 2018.
Shead agreed to a one-year deal with the Seahawks back in July but was released coming out of the preseason. He worked out for the Raiders and Lions since becoming a free agent but left both teams without a contract.
In 2018, Shead appeared in 12 games for the Lions and recorded 18 total tackles and one forced fumble.